From Meiosis to A New Human Being

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Human Reproduction

• From Meiosis to A New Human Being

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Gametogenesis The development and production of
the male and female germ cells (sperm and egg
cells) required to form a new individual.
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Male Reproductive Anatomy

• Sperm is produced in the testes in tubes called
  seminiferous tubules
• The sperm matures and is stored in the epididymis
  until ejaculation

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Sperm cellSperm formation occurs in the
seminiferous tubules of the testis. This process
is started by primitive stem cells called
spermatogonia found on the outer edge of each
tubule. Spermatogonia cells go through rapid
mitotic divisions to build up the stem cell line.
From birth until puberty, all such divisions
simply produce more stem cells.
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Female sex organ
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Uterus and ovary
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oogenesis
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How does an egg mature?

• When a girl is born, all of her future eggs are
  present in the ovaries.
• The future eggs are in suspended animation in
  Prophase I. When a girl reaches puberty, one egg
  each month will develop by completing meiosis.

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Mature Egg
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Fertilization of an Egg
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Ovulation and the pathway of the egg
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Implantation
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From Zygote to Embryo
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From Embryo to Fetus
At the end of the eighth week of development, the
embryo is called a fetus (all of the major organ
systems have formed).
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From Fetus to Baby